Method for retaining and actuating an inter-uterine device inserter and inserter enabling said method to be carried out

Abstract

The subject-matter of the invention is a method of retaining and operating an inserter of an intrauterine contraceptive device, and an inserter permitting the application of this method.To this end, the method which, in an inserter of an intrauterine contraceptive device comprising a sheath 4, a needle 1 housed in the sheath and firmly fixed to a thumb-piece 3, and an intrauterine contraceptive device 15, also housed in the sheath, pulled by the needle and provided with a pull thread 22, consists firstly in firmly fixing needle 1 in relation to sheath 4 and maintaining pull thread 22 in the tensioned state, then in releasing needle 1 and pull thread 22, and is characterised in that the release of needle 1 conjointly ensures the release of pull thread 22.

What is claimed is:  
     
       1. In a method of retaining and operating an inserter of an intrauterine contraceptive(hereinafter IUCD), in which the inserter comprises 
       a sheath;  
       a needle and an IUCD housed in said sheath, said needle being movable relative to said sheath, said needle having a proximal end and a distal end, said needle when housed in said sheath having a first position wherein said distal end does not emerge from said sheath, and a second position wherein said distal end projects a from said sheath when said IUCD is pulled, said proximal end of said needle being fixedly secured to a thumb-piece,  
       said IUCD having a pull thread fixedly secured under tension to said distal end of said needle;  
       said method including the steps of:  
       fixedly securing said needle to said sheath to immobilise said needle in said first position wherein said distal end of said needle does not protrude from said sheath;  
       maintaining said pull thread in a tensioned state to ensure a pulling action between said needle and said IUCD;  
       releasing said pull thread in an operating phase; and,  
       releasing said needle from said first position to place it in said second position during said operating phase whereby said distal end of said needle projects a predetermined distance from said sheath when said IUCD is pulled;  
       the improvement comprising  
       releasing said needle from said first position in said operating phase to conjointly release said pull thread.  
     
     
       2. The method according to  claim 1 , including the steps of, after release of said pull thread, maintaining said pull thread in a free condition during the subsequent operating phase of the inserter, and maintaining said needle in said second position after travel between said first and second positions. 
     
     
       3. The method according to  claim 2 , including the steps of blocking movement of said needle during operation of said inserter on a side being travelled from when said needle is in said first position on said side being travelled from and beyond when said needle is in said second position during operation of said inserter. 
     
     
       4. The method according to  claim 1 , including the steps of simultaneously maintaining tension on said pull thread while immobilizing said needle in said first position. 
     
     
       5. In an inserter for an IUCD comprising 
       a sheath;  
       a needle and an IUCD housed in said sheath, said needle being movable relative to said sheath, said needle having a proximal end and a distal end, and being fixedly secured to a thumb-piece; and,  
       said IUCD having a pull thread, and being fixedly secured under tension to said distal end of said needle  
       the improvement wherein  
       said sheath and said thumb-piece comprise:  
       first cooperating blocking means, said blocking means being adapted to prevent movement of said needle when positioned in a sheath in a first position in which the distal end of said needle does not project from said sheath,  
       means for maintaining said pull thread under tension; and  
       releasing means, said releasing means being actuatable by said thumb-piece, enabling relative movement between said needle and said sheath in a direction of movement of said needle into said sheath, and wherein said releasing means is adapted to release said pull thread of said IUCD.  
     
     
       6. The inserter according to  claim 5 , wherein at least one groove which is substantially parallel to the direction of said needle is provided in at least one of said blocking means of said inserter to ensure said pull thread is maintained in a free state over an operating path of said inserter outside a first position of said first cooperating blocking means, and including second cooperating blocking means, said second blocking means being adapted to block relative movement between said needle and said sheath when said needle is in said second position, without restricting movement of said pull thread. 
     
     
       7. The inserter according to  claim 6 , wherein said second blocking means comprises a projection having a narrow upper portion and a second opening in said sheath, said first and said second openings of said sheath aligned longitudinally and having dimensions corresponding to said narrow upper portion, said second opening and said upper portion being elastically engagable to enable unrestricted movement of said pull thread in said groove. 
     
     
       8. The inserter according to  claim 7 , wherein said projection of said upper portion has a stepped shape in a plane parallel to the plane of said groove, said step being offset from the base of said groove by a distance substantially equal to or greater than a thickness of said pull thread. 
     
     
       9. The inserter according to  claim 6 , wherein said first blocking means comprises a blade and a first notch on said thumb-piece positioned immediately after said stop, said first notch having a face non-adjacent to said stop and shaped as an inclined ramp adapted to pinch said thread in cooperation with said blade and further to dislodge said blade under the effect of longitudinal pressure on said thumb-piece to enable movement of said thumb-piece and said needle. 
     
     
       10. The inserter according to  claim 9 , wherein said second cooperating blocking means comprises a blade and a second notch on said thumb-piece, said second notch being adapted to retain said blade when moved into engagement therewith to ensure retention of said needle relative to said sheath and without blocking said pull thread of said IUCD. 
     
     
       11. The inserter according to  claim 5 , wherein said inserter includes cooperating stop means positioned substantially corresponding to said first and second positions of said needle to thereby limit travel of said needle in said sheath between said first and said second positions. 
     
     
       12. The inserter according to  claim 7 , wherein said cooperating stop means, actuated when said needle occupies said first position in said sheath, comprise a blade formed on said sheath, said blade being elastically deformable whereby a stop on said thumb-piece can pass over said blade, and whereby said blade rebounds behind said stop preventing subsequent movement of said needle when said needle is in said first position. 
     
     
       13. The inserter according to  claim 5 , wherein said first blocking means comprises a first opening in said sheath and a projection on said thumb-piece with a groove permitting said pull thread to pass, said projection being elastically engageable in said first opening in said sheath to block said thumb-piece and movement of said needle with respect to said sheath, and to pinch said pull thread of said IUCD at said base at said groove. 
     
     
       14. The inserter according to  claim 3 , wherein said releasing means comprises a thruster connected to said projection, said thruster being elastically movable to disengage said projection from said first opening and to release relative movement between said needle and said sheath as well as being to release pinching of said pull thread.